The OECD has released guidance on assessing apparent accumulation potential of nanomaterials in fish using Test Guideline 305. Spain developed the document with support from France and the UK, receiving OECD Working Party approval in April 2025.

The guidance addresses the specific challenges of nanomaterial bioaccumulation studies. Traditional octanol-water partitioning approaches are inappropriate for particles, so the document recommends decision trees, dispersion stability pre-tests, and validated feed-spiking methods before conducting full studies.

The document details sampling protocols, storage requirements, and quantitative analysis methods including ICP-OES, ICP-MS, and single-particle ICP-MS for metallic nanomaterials. Current limitations exist for non-metal and carbon nanomaterials. The OECD plans to publish guidance on nanoparticle quantification in biological matrices.

Read the OECD Guidance Document.